Multi-tread vehicles and methods of operating thereof

ABSTRACT

Provided are multi-tread vehicles and methods of operating such vehicles to access small interior spaces. A multi-tread vehicle may include two or more tread sections such that each pair of adjacent tread sections is interconnected by a connector section. Furthermore, each pair may have one or more degrees of articulations, such as being pivotable with respect to each other around one or more axis and/or being bendable with respect to each other around one or more axis. These articulation degrees may be provided by the connector section and/or by couplings between the connector section and each tread section. In some embodiments, each tread section may include two portions detachably coupled to each other. This detachable coupling may be used for disassembly of the multi-tread vehicle after or even during its use, for example, when only a portion of the vehicle needs to be retrieved from an interior space.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to U.S. patent application Ser. No.15/179,493 entitled “Remotely Controlling Robotic Platforms Based onMulti-Modal Sensory Data” filed 2016 Jun. 10 and U.S. patent applicationSer. No. 15/179,542 entitled “Stereoscopic Camera and Associated Methodof Varying a Scale of a Stereoscopic Image Pair” filed 2016 Jun. 10,both of which are incorporated herein by reference in their entirety forall purposes.

BACKGROUND

Accessing small interior spaces, such as wing bays, during assemblyand/or maintenance can be challenging. In many cases, workers accesssuch interior spaces through various access ports, such as ports formedin the bottom skin panels of the wings and through the wing ribs. Thistype of human access requires sufficient large ports, which putslimitation on scaling of various components. For example, a certainminimal wing thickness is needed for access. Furthermore, externalaccess ports need to be closed and even sealed during operation ofaircraft. Finally, many interior spaces have uneven topography such asinternal ribs extending from wing skin panels, which makes it difficultto navigate robotic systems during access. What is needed is a systemfor accessing small interior spaces, such as wing roots and wing tips,and capable of navigating within these spaces which would allowreduction in the number and/size of access ports.

SUMMARY

The following presents a simplified summary of the disclosure in orderto provide a basic understanding of certain embodiments of the presentdisclosure. This summary is not an extensive overview of the disclosureand it does not identify key/critical elements of the present disclosureor delineate the scope of the present disclosure. Its sole purpose is topresent some concepts disclosed herein in a simplified form as a preludeto the more detailed description that is presented later.

Provided are multi-tread vehicles and methods of operating such vehiclesto access small interior spaces. A multi-tread vehicle may include twoor more tread sections such that each pair of adjacent tread sections isinterconnected by a connector section. Furthermore, each pair may haveone or more degrees of articulations, such as being pivotable withrespect to each other around one or more axis and/or being bendable withrespect to each other around one or more axis. These articulationdegrees may be provided by the connector section and/or by couplingsbetween the connector section and each tread section. In someembodiments, each tread section may include two portions detachablycoupled to each other. This detachable coupling may be used fordisassembly of the multi-tread vehicle after or even during its use, forexample, when only a portion of the vehicle needs to be retrieved froman interior space.

In some embodiments, a multi-tread vehicle comprises a first treadsection, a second tread section, and a connector section coupled to thefirst rear tread portion and to the second front tread section. Thefirst tread section may comprise a first front tread portion and a firstrear tread portion detachably coupled to the first front tread portionusing a first detachable tread coupling. The first front tread portionmay comprise a first front right tread and a first front left tread. Thefirst rear tread portion may comprise a first rear right tread and afirst rear left tread. The second tread section may comprise a secondfront tread portion and a second rear tread portion detachably coupledto the second front tread portion using a second detachable treadcoupling. The second front tread portion may comprise a second frontright tread and a second front left tread. The second rear tread portionmay comprise a second rear right tread and a second rear left tread. Itshould be noted that first, second, front, rear, left, and right areused for distinguishing purposes only and are not limiting to spatialorientations of the components during operation of the multi-treadvehicle which may change.

In some embodiments, the connector section is pivotable relative to thefirst rear tread portion around a first rear pivot axis. The first rearpivot axis is perpendicular to the plane defined by the first rear righttread and the first rear left tread. In some embodiments, the connectorsection is further pivotable relative to the second front tread portionaround a second front pivot axis perpendicular to the plane defined bythe first rear right tread and the first rear left tread. The distancebetween the first rear pivot axis and the second front pivot axis mayrepresent a larger portion of the length of the connector section.

In some embodiments, the multi-tread vehicle is foldable between anextended state and a folded state. In the extended state, the firstfront right tread and the second front right tread are collinear. In thefolded state, the first front left tread is disposed between the firstfront right tread and the second front right tread. Furthermore, in thefolded state, the first front left tread is adjacent to and parallel tothe second front right tread.

In some embodiments, the first front tread portion comprises a firstfront pivot axis. The distance between the first rear pivot axis and thesecond front pivot axis may be equal to the square root of the sum ofthe square of the distance between the first front pivot axis and firstrear pivot axis and the square of the distance between the first frontpivot axis and the second front pivot axis. In some embodiments, thedistance between the first front pivot axis and the second front pivotaxis is equal to a width of the first tread section.

In some embodiments, the first rear tread portion comprises a rear pivotdrive engaging the connector section for pivoting the connector sectionrelative to the first rear portion. The first rear portion may comprisea rear tread pivot coupling engaging the front connector pivot couplingof the connector section.

In some embodiments, the front end of the connector section is bendablerelative to the rear end of the connector section around the front bendaxis. The front bend axis may be parallel to the plane defined by thefirst rear right tread and the first rear left tread. Furthermore, thefront connector pivot coupling of the connector section may be bendablerelative to a rear connector pivot coupling of the connector sectionaround the front bend axis.

In some embodiments, the front end of the connector section is furtherbendable relative to the rear end of the connector section around a rearbend axis. The rear bend axis may be parallel to the plane defined bythe first rear right tread and the first rear left tread.

In some embodiments, the connector section comprises a front connectorbend drive for bending the front end relative to the rear end of theconnector section around the front bend axis.

In some embodiments, the connector section comprises a front connectorportion and a rear connector portion detachably coupled to the frontconnector portion using a detachable connector coupling. The connectorsection may comprise a power transmission linkage interconnected to thefirst tread section and to the second tread section.

In some embodiments, the plane defined by the first front right treadand the first front left tread coincide with the plane defined by thesecond front right tread and the second front left tread. During motionof the multi-tread vehicle these planes may continue to coincide or atleast remain parallel in some embodiments.

The first front right tread and the first front left tread may havedifferent lengths. The first front right tread and the first rear lefttread may have same lengths. Furthermore, the first rear right tread andthe first front left tread have same lengths. In some embodiments, thefirst rear left tread overlaps a right tread gap between the first frontright tread and the first rear right tread. Furthermore, the first frontright tread overlaps a left tread gap between the first front left treadand the first rear left tread.

In some embodiments, the first front right tread and the first rearright tread are collinear. The first front left tread and the first rearleft tread may also be collinear.

The first front tread portion may comprise a front tread drive coupledto the first front right tread and the first front left tread. In someembodiments, the front tread drive is operable to independent controlspeeds of the first front right tread and the first front left tread.The first rear portion may comprise a rear tread drive coupled to thefirst rear right tread and the first rear left tread. The first reartread drive may control the speeds of the first rear right tread and thefirst rear left tread independently from speeds of the first front righttread and the first front left tread.

In some embodiments, the first tread section and the second treadsection are identical. The second tread section may be coupled to atether. The multi-tread vehicle may comprise one or more proximitysensors. The multi-tread vehicle may comprise a camera and a light.

In some embodiments, the first detachable tread coupling and the seconddetachable tread coupling are remotely controlled using, for example awire linkage of the connector section. In some embodiments, at least thefirst detachable tread coupling comprises an interlocking mechanism. Atleast the first detachable tread coupling may comprise an connectorelectrically coupled to a wire linkage of the connector section. Thisconnector may provide one or more electrical, pneumatic, and/orhydraulic connections as well as mechanical rigidity to the detachablecoupling. In some embodiments, the connector may be a part of one ormore of control lines (e.g., electrical, fiber optic, and the line),hydraulic lines, and/or pneumatic lines of the multi-tread vehicle.

Provided also is a method for accessing an interior space of aircraftusing a multi-tread vehicle. The method may comprise positioning themulti-tread vehicle at an opening to the interior space of aircraft andadvancing at least the first tread section of the multi-tread vehicle atan opening to the interior space.

In some embodiments, the multi-tread vehicle comprises a first treadsection, a second tread section, and a connector section coupled to thefirst rear tread portion and to the second front tread section. Thefirst tread section may comprise a first front tread portion and a firstrear tread portion detachably coupled to the first front tread portionusing a first detachable tread coupling. The first front tread portionmay comprise a first front right tread and a first front left tread. Thefirst rear tread portion may comprise a first rear right tread and afirst rear left tread. The second tread section may comprise a secondfront tread portion and a second rear tread portion detachably coupledto the second front tread portion using a second detachable treadcoupling. The second front tread portion may comprise a second frontright tread and a second front left tread. The second rear tread portionmay comprise a second rear right tread and a second rear left tread.

In some embodiments, advancing the first tread section comprisesrotating the first front right tread and the first front left treadwhile the first front right tread and the first front left tread contacta portion of an edge defining the opening. In some embodiments, thefirst tread section and the connector section are collinear whileadvancing the first tread section. In some embodiments, the first treadsection is simultaneously supported by at least two edges for at leastfor a period of time while advancing the first tread section.

In some embodiments, the method further comprises pivoting the firsttread section relative to the connector section. Pivoting the firsttread section may at least partially overlap in time with advancing thefirst tread section. Pivoting the first tread section may be performedwhile both the first tread section and the connector section arepositioned within the interior space. Furthermore, the method maycomprise pivoting the second tread section relative to the connectorsection while advancing the first tread section into the interior space.

In some embodiments, the method further comprises bending the connectorsection. Bending the connector section may at least partially overlap intime with advancing the first tread section.

These and other embodiments are described further below with referenceto the figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic illustration of an aircraft, in accordance withsome embodiments.

FIGS. 1B and 1C are schematic cross-sectional views of the wing of theaircraft illustrated in FIG. 1A, in accordance with some embodiments.

FIGS. 2A and 2B are schematic side and top views of a multi-treadvehicle, in accordance with some embodiments.

FIGS. 3A-3C are schematic views of a tread section of a multi-treadvehicle and portion of the tread section, in accordance with someembodiments.

FIGS. 4A-4C are schematic cross-sectional views of a detachable treadcoupling at different states, in accordance with some embodiments.

FIGS. 5A-5B are schematic views of a connector section of a multi-treadvehicle, in accordance with some embodiments.

FIGS. 6A-6C are schematic top views of a multi-tread vehicle duringdifferent folding states, in accordance with some embodiments.

FIG. 6D is a schematic top view of a multi-tread vehicle in the foldedstate showing different lengths between pivot axes, in accordance withsome embodiments.

FIGS. 6E-6F are schematic top views of a multi-tread vehicle havingmultiple tread and connector sections, in accordance with someembodiments.

FIGS. 7A-7B are schematic side views of a multi-tread vehicle showingbending of connector sections of the vehicle, in accordance with someembodiments.

FIGS. 7C-7E are schematic illustrations of deployment of a multi-treadvehicle into a wing through a lower wing skin panel, in accordance withsome embodiments.

FIGS. 8A and 8B are schematic top and side views of a multi-treadvehicle showing a combination of bending and pivoting, in accordancewith some embodiments.

FIG. 9 is a schematic side view of a multi-tread vehicle showingdifferent sensors, cameras, and lights of the vehicle, in accordancewith some embodiments.

FIG. 10 is a process flowchart corresponding to a method for accessingan interior space using a multi-tread vehicle, in accordance with someembodiments.

FIGS. 11A-11D are schematic views of multi-tread vehicles withininterior spaces at different stages of the method, in accordance withsome embodiments.

FIG. 12 is a block diagram of aircraft production and servicemethodology that may utilize methods and assemblies described herein.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth inorder to provide a thorough understanding of the presented concepts. Thepresented concepts may be practiced without some or all of thesespecific details. In other instances, well known process operations havenot been described in detail so as to not unnecessarily obscure thedescribed concepts. While some concepts will be described in conjunctionwith the specific embodiments, it will be understood that theseembodiments are not intended to be limiting. On the contrary, it isintended to cover alternatives, modifications, and equivalents as may beincluded within the spirit and scope of the present disclosure asdefined by the appended claims.

For example, the techniques of the present disclosure will be describedin the context of particular aircraft structures, such as interior wingbay compartments. However, it should be noted that the techniques andmechanisms of the present disclosure apply to various other confined andlimited spaces and/or structures such as flaps, stabilizers, rudders,slats, ailerons, reels, crowns, and the like. In the followingdescription, numerous specific details are set forth in order to providea thorough understanding of the present disclosure. Particular exampleembodiments of the present disclosure may be implemented without some orall of these specific details. In other instances, well known processoperations have not been described in detail in order not tounnecessarily obscure the present disclosure.

Throughout the present disclosure, the terms “front,” “rear,” “first,”“second,” “right,” and “left” may be used to describe particularelements in the following figures. However, such terms are used merelyfor identification and descriptive purposes and are not meant tospecifically fix any element in any particular position or orientation.For example, when advancing the multi-tread vehicle in its operatingenvironment the rear tread portion may be moving ahead of the fronttread portion. In the same or another example, a second front treadsection may be ahead of a first front tread section. Likewise, the rightand left orientations are relative to the position of an observer andmay change as the multi-tread vehicle moves. For purposes of thisdisclosure, a “tread” is defined as a continuous track, a continuousband of treads, a continuous band of track plates, or other like devicessupported by at least two wheels and driven by at least one of thesewheels. Various techniques and mechanisms of the present disclosure willsometimes be described in singular form for clarity. However, it shouldbe noted that some embodiments include multiple iterations of atechnique or multiple instantiations of a mechanism unless notedotherwise.

Introduction

The present disclosure describes a novel multi-tread vehicle foraccessing interior spaces, such as wing bays to conduct assembly,repair, and inspection tasks. The multi-tread vehicle may be alsoreferred to as a robotic arm and includes multiple tread sections suchthat each pair of adjacent tread sections is interconnected by aconnector section. Each tread section includes multiple treadsconfigured to engage supporting structures inside the interior space andto move this tread section and, as a result, the corresponding portionof the multi-tread vehicle within the interior space. In other words,the treads of each tread section are used to advance the vehicle withinthe interior space. Each pair of adjacent tread sections may bearticulated with respect to each other such as pivot with respect toeach other around one or more axes and/or bend with respect to eachother around one or more axes. For example, pivoting articulations maybe used to extend the multi-tread vehicle into the interior space and/orto fold into a compact format (e.g., a storage magazine). In someembodiments, the pair of adjacent tread sections are articulated withall pivot axes aligned vertically to allow passive support ofcantilevered deployment.

In some embodiments, the multi-tread vehicle is used to access theinterior of an aircraft wing through various access ports positionedthrough rib, spar support structures, lower and upper wing skin panels,and the like. The multi-tread vehicle may be configured to span at leastone wing bay compartment such that it is supported by at least twobottom edges of each access port. More specifically, the length of eachtreaded section and the length of the connector section may be such thatthe pair of adjacent treaded section is always supported by at least twostructures (e.g., bottom edges of access ports) within the interiorspace.

FIG. 1A is a schematic illustration of aircraft 100, in accordance withsome embodiments. As depicted in FIG. 1A, aircraft 100 is defined by alateral axis (X-axis), a longitudinal axis (Y-axis), and a vertical axis(Z-axis). In various embodiments, aircraft 100 comprises airframe 150with interior 170. Aircraft 100 includes right wing 120 and left wing121 coupled to airframe 150. Aircraft 100 also includes engine 130coupled to right wing 120 and engine 131 coupled to left wing 121. Insome embodiments, aircraft 100 further includes a number of high-levelinspection systems 140 and 160, further described below in conjunctionwith FIG. 12. Aircraft 100 shown in FIG. 1A is one example in which afoldable robotic arm, such as multi-tread vehicle 200, may beimplemented to access interior 126 of wings 120 and/or 121 to conductassembly, repair, and/or other inspection tasks, in accordance with anillustrative embodiment.

FIGS. 1B and 1C are schematic cross-sectional views of wing 120 and/orwing 121 of aircraft 100 illustrated in FIG. 1A, in accordance with someembodiments. Specifically, FIG. 1B is a lateral cross-section of wing120 from the A-A viewpoint (identified in FIG. 1A) corresponding to thelateral axis. FIG. 1C is a horizontal bottom-view cross-section of wing120 from the B-B viewpoint (identified in FIG. 1A) corresponding to thevertical axis. As depicted in FIGS. 1B and 1C, wing 120 may be asemi-hollow structure having interior space 126. Wing 120 is defined byleading edge 120 a, trailing edge 120 b, inboard end 120 c, and outboardend 120 d. As depicted in FIG. 1B, wing 120 includes one or more ribs122. Each rib 122 comprises a thin structure that may extend fromleading edge 120 a of wing 120 to trailing edge 120 b of wing 120.Specifically, each rib 122 may extend in the direction perpendicular tothe lateral axis (X-axis) of aircraft 100.

In some embodiments, wing 120 includes one or more ribs 122.Specifically, FIG. 1C identifies rib 122 a, rib 122 b, and 122 c.However, one having ordinary skill in the art would understand that anynumber of ribs 122 may be positioned within interior space 126. In someembodiments, multiple ribs 122 are configured along the lateral axis(x-axis) of aircraft 100, between inboard end 120 c and outboard end 120d, separating interior 126 into one or more wing bay compartments. Insome embodiments, ribs 122 are placed at equal intervals such that thewidth of each wing compartment between ribs 122 is equal in length. Invarious embodiments, ribs 122 may be manufactured from metal, carbonfiber, woods and/or other suitable materials and contribute to givingshape to wing 120 and/or serve as attachment points for controlsurfaces, flaps, undercarriage, and engines 130 and 131. In someembodiments, rib 122 a defines the inboard end 120 c, and may also beknown as a compression rib or a bulkhead rib.

As depicted in FIG. 1B, wing 120 includes one or more openings 124defined by edges 125. In some embodiments, openings 124 are access portsallowing advancement of multi-tread vehicle 200 into wing 120 andthrough ribs 122. The cross-sectional view of FIG. 1B depicts rib 122with three openings 124. However, rib 122 may include more or feweropenings 124. In some embodiments, openings 124 are equal in size.Openings 124 may be aligned along the Y direction or may be offset withrespect to each other in the Z direction (e.g., staggered in the Zdirection with respect to each other). In some embodiments, one or moreopenings 124 or access ports may provide access into wing 120 from edge120 a, and other openings 124 may be located on spars, or other supportstructures, that run laterally along wing 120 from inboard end 120 c tooutboard end 120 d.

In some embodiments, one or more openings 124 of one rib 122 are alignedwith one or more openings 124 of another rib 122 as schematically shownin FIG. 1C illustrating the bottom cross-sectional view of wing 120.Ribs 122 may extend parallel to each, which means openings 124 providedon different ribs may extend parallel to each other. Furthermore, edges126 of opening 124 may extend parallel to each other as a result. Insome embodiments, aligned openings 124 may define operating paths withininterior space 126, such as interior operating paths 126 a, 126 b, and126 c, depicted as shaded areas in FIG. 1C. In various embodiments,openings 124 may allow a foldable robotic arm, or other mechanicaldevice, such as multi-tread vehicle 200, to access various portions ofwing bays within interior space 126 of wing 120 that are separated byribs 122. In some embodiments, openings 124 may not be linearly aligned,such that an internal operating paths, has a curved configuration.

Examples of Multi-Tread Vehicles

FIGS. 2A and 2B are schematic side and top views of multi-tread vehicle200, in accordance with some embodiments. According to variousembodiments, multi-tread vehicle 200 comprises first tread section 210a, second tread section 210 b, and connector section 280 coupled tofirst tread section 210 a and to second tread section 210 b. Each offirst tread section 210 a and second tread section 210 b may includemultiple treads. In the depicted example, first tread section 210 aincludes first front tread portion 212 a and first rear tread portion214 a, such that first front tread portion 212 a comprises first frontright tread 222 a and first front left tread 224 a while first frontrear portion 214 a comprises first rear right tread 226 a and first rearleft tread 228 a. First front tread portion 212 a and first rear treadportion 214 a may be coupled by first detachable tread coupling 230 a asfurther described below. First tread section 210 a may be pivotablycoupled to connector section 280 defined by first rear pivot axis 293 a.FIG. 2B also illustrates first front pivot axis 291 a allowing firsttread section 210 a to pivot about axis 291 a relative to anotherconnector section as further described below with reference to FIGS.6A-6C.

Second tread section 210 b and any other tread sections, if present, mayhave a design similar to first tread section 210 a. In some embodiments,all tread sections of multi-tread vehicle 200 are identical. As shown inFIGS. 2A and 2B, second tread section 210 b may include second fronttread portion 212 b and second rear tread portion 214 b, such thatsecond front tread portion 212 b comprises second front right tread 222b and second front left tread 224 b while second rear tread portion 214b comprises second rear right tread 226 b and second rear left tread 228b. Second front tread portion 212 b and second rear tread portion 214 bmay be coupled using second detachable tread coupling 231. Furthermore,second tread section 210 b may have corresponding second front pivotaxis 291 b and second rear pivot axis 293 b when second tread section210 b is pivotably coupled to connector sections, as further describedbelow with reference to FIGS. 6A-6C.

As shown in FIGS. 2A and 2B, connector section 280 may include front end280′ and rear end 280″ such that front end 280′ faces first treadsection 210 a and rear end 280′ faces second tread section 210 b.Similar to tread sections, connector section 280 may also include twoportions detachably coupled by detachable connector coupling 270, asfurther described below with reference to FIGS. 5A-5B and FIGS. 4A-4C.In some embodiments, connector section 280 may include one or more offront bend axis 292 and rear bend axis 294 as further described belowwith reference to FIGS. 5A-5B and FIGS. 7A-7C.

In some embodiments, front end 280′ of connector section 280 is coupledto first tread section 210 a at first rear tread portion 214 a. rear end280″ of connector section 280 may be coupled to second tread section 210b at second front tread section 212 b. The coupling between connectorsection 280 and first tread section 210 a may be pivotable and definedby first rear pivot axis 293 a. Likewise, the coupling between connectorsection 280 and second tread section 210 b may be pivotable and definedby second front pivot axis 291 b. In some embodiments, the distancebetween first rear pivot axis 293 a and second front pivot axis 291 bmay represent a larger portion of length of connector section 280.Connector section 280 may be equal in length to both first tread section210 a and second tread section 210 b. In some embodiments, the distancebetween first rear pivot axis 293 a and second front pivot axis 291 band the lengths of corresponding sections are such that first treadsection 210 a and second tread section 210 b can fold in order to stackadjacent to each other in folded state 600, as further described belowand in conjunction with FIGS. 6A-6D. Furthermore, the gap between firsttread section 210 a and second tread section 210 b may be less than thedistance between adjacent support points (e.g., ribs 122 of wing 120)when multi-tread vehicle 200 is advanced with its operating environment.Likewise, the length of each tread section 210 may be greater than thatdistance between adjacent point. As such, when first tread section 210 areaches a new support point before second tread section 210 b leaves itssupport point and vice versa.

As noted above, connector section 280 may pivot relative to first reartread portion 214 a around first rear pivot axis 293 a. First rear pivotaxis 293 a may be perpendicular to plane 290 a defined by first rearright tread 226 a and first rear left tread 228 a. Specifically, plane290 a may be defined by support points of first rear right tread 226 aand first rear left tread 228 a during operation of multi-tread vehicle200.

Connector section 280 may be also pivotable relative to second fronttread portion 212 b around second front pivot axis 291 b. Second frontpivot axis 291 b may be also perpendicular to plane 290 a or to plane290 b defined by second front right tread 222 b and second front lefttread 224 b. In some embodiments, plane 290 a coincides with plane 290b. During motion of multi-tread vehicle 200 these planes 290 a and 290 bmay continue to coincide (e.g., when connector section 280 does not bendrelative to either tread portion and multi-tread vehicle 200 remainsplanar) or at least remain parallel (e.g., when connector section 280 issynchronously bent with respect to both adjacent tread sections by thesame angle by in the opposite direction).

In some embodiments, tread sections 210 a and 210 b and connectorsection 280, may be constructed from any suitable materials including,but not limited to, metals, plastics, fiberglass, etc., or combinationof materials that provides the desired strength, flexibility,durability, weight, water resistance, or other desired physicalcharacteristic.

Examples of Tread Sections

FIGS. 3A-3C illustrate schematic views of one tread section 210 ofmulti-tread vehicle 200, in accordance with some embodiments. Treadsection 210 depicted in FIG. 3A may be tread section 210 a or 210 bpreviously described in FIGS. 2A and 2B. FIG. 3B depicts a top-down viewof tread section 210. As noted below, tread section 210 may comprisefront tread portion 212 and rear tread portion 214. Front tread portion212 and rear tread portion 214 may be identical structures rotated 180degrees relative to one another. Furthermore, front tread portion 212and rear tread portion 214 may be detachably coupled to each other bydetachable tread coupling 230 formed by a part of detachable treadcoupling 230 of front tread portion 212 and a part of detachable treadcoupling 230 of rear tread portion 214.

Tread section 210 also includes front tread pivot coupling 211 and reartread pivot coupling 213 for coupling, for example, to two separateconnector sections. Tread pivot coupling 213 may include drives forpivoting tread section 210 relative to a corresponding connectorsection. In some embodiments, tread pivot coupling 213 compriseselectrical, pneumatic, hydraulic, signal, and/or other types ofconnections for connecting tread section 210 to the correspondingconnector section. Alternatively, one or more of these connections maybe provided between tread section 210 and the corresponding connectorsection away from tread pivot coupling 213.

Front tread pivot coupling 211 may be a part of front tread portion 212,while rear tread pivot coupling 213 may be a part of rear tread portion214. It should be noted that when front tread portion 212 and rear treadportion 214 are detached from each other, tread pivot couplings 211 and213 may be remain coupled to their respective connector sections.

Pivot axes may be centered within the tread pivot couplings, such asfirst rear pivot axis 293 a and second front pivot axis 291 b. Forexample, referring to FIGS. 2A and 2B, front tread pivot coupling 211may be located on first front tread portion 212 a and centered aroundfirst front pivot axis 291 a, or on second front tread portion 212 b andcentered around second front pivot axis 291 b. Additionally, rear treadpivot coupling 213 may be located on first rear tread portion 214 a andcentered around first rear pivot axis 293 a, or on second rear treadportion 214 b and centered around second rear pivot axis 293 b.

Furthermore, as noted above, tread section 210 includes front righttread 222, front left tread 224, rear right tread 226, and rear lefttread 228. Front right tread 222 and front left tread 224 may be partsof front tread portion 212, while rear right tread 226 and rear lefttread 228 may be parts of rear tread portion 214. In some embodiments,the lengths of treads 222, 224, 226, and 228 may vary in length. Asdepicted in FIGS. 3A and 3B, front right tread 222 and front left tread224 have different lengths, with front right tread 222 being longer thanfront left tread 224 in this particular example. Additionally, rearright tread 226 and rear left tread 228 may have different lengths withrear left tread 228 being longer than rear right tread 226, in thisexample. These differences in tread lengths offset the right tread gap223 and left tread gap 224, for example, in the X direction as shown inFIG. 3B. This offset allows for tread section 210 to travel through aminimal support surface (e.g., a rib) while being supported by at leastone tread at all times. In some embodiments, front right tread 222 andrear left tread 228 have the same lengths, and rear right tread 226 andfront left tread 224 have the same lengths.

Front right tread 222 and rear right tread 226 may be collinear.Furthermore, Front right tread 222 and rear right tread 226 may beseparated by right tread gap 223. Similarly, front left tread 224 andrear left tread 228 may also be collinear. Furthermore, front left tread224 and rear left tread 228 may be separated by left tread gap 225. Insome embodiments, the lengths and orientations of treads 222, 224, 226,and 228 are configured such that rear left tread 228 overlaps righttread gap 223 between front right tread 222 and rear right tread 226.Furthermore, the treads may be configured such that front right tread222 overlaps left tread gap 225 between first front left tread 224 andrear left tread 228.

The significance of the gaps and overlaps is such that when treadsection 210 or, more generally, multi-tread vehicle 200 is advanced,front right tread 222 and rear right tread 226 may lose contact with asupporting structure (e.g., an edge) while right tread gap 223 ispassing over this supporting structure. Likewise, right tread 222 andrear right tread 226 may lose contact with a supporting structure (e.g.,an edge) while left tread gap 225 is passing over this supportingstructure. To ensure that at least one of front right tread 222, frontleft tread 224, rear right tread 226, and rear left tread 228continuously maintain contact with the supporting structure, right treadgap 223 and left tread gap 225 may be offset from each other and overlapwith corresponding treads.

In some embodiments, front right tread 222 and front left tread 224extend beyond the uncoupled (to another portion) end of front treadportion 212, and rear right tread 226 and rear left tread 228 extendbeyond the uncoupled end of rear tread portion 214. Such configurationallows the treads to make contact with structures situated above plane290 a and/or 290 b, and prevent contact between such structures withnon-treaded bodies of front tread portion 212 and/or rear tread portion214. As such, tread section 210 may have some climbing capabilitiesprovided by its threads. These capabilities may be further enhanced bybending of multi-tread vehicle 200 as further described below withreference to FIG. 5A and FIGS. 7-8.

In some embodiments, front right tread 222, front left tread 224, rearright tread 226, and rear left tread 228 may be constructed of rubber,metal, or other material or combination of materials that provides thedesired strength, flexibility, durability, grip, or other desiredphysical characteristic for a moving tread mechanism. To propel treadsection 210, treads 222, 224, 226, and 228 may be coupled to treaddrives, such as front tread drive 232 and rear tread drive 234. As shownin FIG. 3A, front tread portion 212 comprises front tread drive 232coupled to front right tread 222 and front left tread 224. Specifically,front right tread 222 and front left tread 224 may be each coupled to aseparate wheel structures, of front tread drive 232, such as front leftdrive wheel 236 a shown in FIG. 3A. Front right tread 222 and front lefttread 224 may be each further coupled to a supporting wheel structures,such as front left non-drive wheel 238 a. As further depicted in FIG.3A, rear tread portion 214 may comprise rear tread drive 234 coupled torear right tread 226 and rear left tread 228. In some embodiments, rearright tread 226 and rear left tread 228 are each coupled to wheelportions of rear tread drive 234, such as rear left drive wheel 236 b.In some embodiments, rear right tread 226 and rear left tread 228 areeach further coupled to a supporting wheel structures, such as rear leftnon-drive wheel 238 b.

Front right tread 222 and front left tread 224 may be driven by the samedrive, e.g., front tread drive 232, or different drives. For example,each of front right tread 222 and front left tread 224 may be coupled toa separate drive thereby allowing for different speeds of front righttread 222 relative to front left tread 224. This approach is furtherdescribed below and may be also used for rear right tread 226 and rearleft tread 228.

Because front tread portion 212 and rear tread portion 214 may beidentical structures rotated 180 degrees, rear left drive wheel 236 band rear left non-drive wheel 238 b may be representative of a frontright drive wheel and a front right non-drive wheel that would becoupled to front right tread 222, respectively. Moreover, front leftdrive wheel 236 a and front left non-drive wheel 238 a may berepresentative of a rear right drive wheel and a rear right non-drivewheel that would be coupled to rear right tread 226, respectively. Insome embodiments, supporting wheel structures, such as 238 a and 238 b,may also be coupled to additional tread drives.

In some embodiments, the wheel portions of front tread drive 232 andrear tread drive 234, such as front left drive wheel 236 a and rear leftdrive wheel 236 b, include protrusions 236′, such as sprockets 236″and/or claws 236′″, to grip sections of treads 222, 224, 226, and 228 tocause the corresponding treads to wind around the wheel portions.Supporting wheel structures, such as non-drive wheels 238 a and 238 b,may also include such protrusions 236′. In some embodiments, suchprotrusions grip treads 222, 224, 226, and 228 at perforations and/orindentations on the interior surface of the treads. Treads 222, 224,226, and 228 may be a single continuous band, such as a belt of multiplelink plates that couple together by joint hinges to form a continuoustrack of link plates. In some embodiments, treads 222, 224, 226, and 228may include a combination of tread protrusions and/or grooves on theexterior surface set in various patterns in order to improve grip ortraction with a surface.

In some embodiments, front tread drive 232 and rear tread drive 234 maycomprise a motor arrangement comprising a motor and a gear drive forrotational movement of wheel portions. For example, the motor may be aDC motor, stepper motor, and/or servo motor. In some embodiments, themotor arrangement further comprises a transmission and gear arrangement.Each tread drive, such as front tread drive 232, may rotate wheelportions, such as front left drive wheel 236 a or rear left drive wheel236 b, in a clockwise direction, counterclockwise direction, or anycombination thereof to move the treads. In some embodiments, a treaddrive, such as front tread drive 232, is configured to rotate wheelportions on each side of a tread portion, such as front tread portion212, at different speeds.

In some embodiments, each tread drive is synchronously operated tosimultaneously rotate treads 222, 224, 226, and 228 in order to propelmulti-tread vehicle 200 in a forward and/or backward direction. Thespeed of 222, 224, 226, and 228 may be the same while advancing treadsection 210 or different, for example, when turning tread section 210.Multi-tread vehicle 200 may be advanced in this way into interior 126 ofwing 120 by advancing over and being supported by edges 125 of accessport openings 124 by treads 222, 224, 226, and 228.

In some embodiments, front tread drive 232 is operable to independentlycontrol speeds and/or directions of front right tread 222 and front lefttread 224. In some embodiments, rear tread drive 234 is operable toindependent control speeds and/or directions of rear right tread 226 andrear left tread 228. rear tread drive 234 may control speeds of rearright tread 226 and rear left tread 228 independently from speedscontrolled by front tread drive 232 for front right tread 222 and frontleft tread 224. In some embodiments, a motor arrangement is located atdifferent sides of respective thread portions and away from detachabletread coupling.

In various embodiments, connector section 280 couples to one or moretread sections, such as first tread section 210 a and second treadsection 210 b as shown in FIGS. 2A and 2B. For example, connectorsection 280 may engage front tread pivot coupling 211 of second treadsection 210 b and/or rear tread pivot coupling 213 of first treadsection 210 a. Connector section 280 may include its own connector pivotcoupling for such purposes, such as front connector pivot coupling 281and/or rear connector pivot coupling 283. For example, as shown in FIGS.5A and 5B, front connector pivot coupling 281 located at front end 280′of connector section 280 and may be engaged with rear tread pivotcoupling 213 of first rear tread portion 214 a. rear connector pivotcoupling 283 at rear end 280″ of connector section 280 may also beengaged with front tread pivot coupling 211 of second front treadportion 212 b.

As depicted in FIG. 3B, tread section 210 may further include pivotdrives, such as front pivot drive 242 and rear pivot drive 244. Frontpivot drive 242 and/or rear pivot drive 244 may act on connector section280 to cause pivot of connector section 280 about a corresponding pivotaxis, such as first rear pivot axis 293 a for and/or second front pivotaxis 291 b. For example, rear pivot drive 244 may be located on firstrear tread portion 214 a and cause connector section 280 to pivotrelative to first rear tread portion 214 a around first rear pivot axis293 a. As another example, front pivot drive 242 may be located onsecond front tread portion 212 b and cause connector section 280 topivot relative to second front tread portion 212 b around second frontpivot axis 291 b. In some embodiments, such pivoting capability mayprovide greater mobility and compact folding of multi-tread vehicle aswill be described in FIGS. 6A-6F.

In some embodiments, pivot drives 242 and/or 244 comprise a motor 242′and/or 244′ and, in some instances, a gear drive for pivoting treadsection 210 and/or connector section 280 relative to each other aroundan axis, such as axis 293 a. For example, motor 242′ and/or 244′ may bea DC motor, stepper motor, and/or servo motor. In some embodiments, themotor arrangement further comprises a transmission mechanism and/or geararrangement. In some embodiments, pivot drives, similar to drives 242and/or 244, are positioned on connector section 280. If it is desirableto keep the size (e.g., thickness 283) of connector section 280 to theminimum, then drives 242 and/or 244 may be kept on tread section 210.Because tread section 210 necessarily includes treads and tread drives,it will typically be larger in size (e.g., have a greater thickness 283)than connector section 280 and may be more suitable for drives 242and/or 244.

In some embodiments, front tread portion 212 and rear tread portion 214are detachable units that are attached together (e.g., during someoperation) by detachable tread coupling 230. Detachable tread coupling230 may comprise front part and rear part, which belong to respectivetread portions 212 and 214. At some point during operation, detachabletread coupling 230 may detach front tread portion 212 from rear treadportion 214, which may be used, for example, to retain one of theseportions within interior 126 while removing the other portion. FIG. 3Cdepicts a single tread portion, such as rear tread portion 214 ofmulti-tread vehicle 200. In this view, rear tread portion 214 isdecoupled from front tread portion 212.

As depicted in FIGS. 3B and 3C, a part of detachable tread coupling 230of rear tread portion 214 may comprise a structure with two protrusions,inner protrusion 230-1 and outer protrusion 230-2, which may be viewedas a set of interdigitated and/or interlocking protrusions. Detachabletread coupling portion 230 b may further include interlocking mechanism235 and connectors 237 located on each protrusion. In some embodiments,a part of detachable tread coupling portion 230 corresponding to fronttread portion 212 includes an identical configuration, including theinner protrusion and the outer protrusion. The two parts of detachablecoupling portions 230 may hermaphroditically engage such that fronttread portion 212 and rear tread portion 214 couple to form completetread section 210, such as first tread section 210 a or second treadsection 210 b. It should be noted that connectors 237 may also providemechanical rigidity to detachable tread coupling 230. Furthermore,connectors may provide one or more electrical couplings between fronttread portion 212 and rear tread portion 214 (e.g., for powertransmission and/or electrical controls), one or more fiber opticcouplings, one or more hydraulic couplings, and/or one or more pneumaticcouplings.

As geometrically identical components, the protrusions of detachabletread coupling 230 on each tread portion 212 and 214 form hermaphroditicmating configuration 230′ that includes simultaneous male component230-1′ and female component 230-1″, involving complementary pairedidentical parts each containing both protrusions and cavities. Suchmating surfaces can freely pair with any other, provided that the sizeand type are already matched. For example, as shown in FIGS. 2A-2B,first front right tread portion 212 a is interlocked with first reartread portion 214 a, but can also interlock with any of second fronttread portion 212 b or second rear tread portion 214 b, due to thehermaphroditic tread coupling portions. In other embodiments, detachabletread couplings 230 a and/or 230 b, may include more or fewerprotrusions and/or cavities.

Referring to FIG. 4A, detachable coupling 230 engages and are secured inplace by interlocking mechanisms 235 within each protrusion 230-1,230-2, 230-3, and 230-4. Interlocking mechanisms 235 control one or morepins 235′ along each protrusion that interconnect with one or morecavities 235″ along an adjacent protrusion. For example, detachabletread coupling 230 may include one pin 235′ at the interior side of thetip of each protrusion. Inner protrusions 230-1 and 230-3 may includecorresponding cavities 235″ on each side at the base. Once the parts ofdetachable tread coupling 230 a have been paired together, pins 235′ oneach protrusion fit into corresponding cavities 235″ of each innerprotrusion, causing front tread portion 212 and rear tread portion 214to lock together securely. Alternative mechanical mechanisms andconfigurations may be implemented to secure the tread portions, asdescribed in FIGS. 4A-4C.

In various embodiments, tread coupling 230 allows for modular assemblyand disassembly of multi-tread vehicle 200. During operation, portionsof the multi-tread vehicle 200 can be assembled and/or disassembled(e.g., using control instructions) in a confined space, such as a wingbay compartment of interior 126 of wing 120. It should be noted thatdetachable connector couplings 270 and/or detachable tread couplings 230can be actuated remotely. For example, one of these couplings may bedecoupled while multi-tread vehicle 200 is deployed in its operatingenvironment to remove only a portion of multi-tread vehicle 200 fromthat environment while retaining the remaining portion in theenvironment. In some embodiments, certain portions of multi-treadvehicle 200 may be disassembled in case of failures or malfunctions ofcertain components, allowing for multi-tread vehicle 200 to beserviceable inside an aircraft wing, such as wing 120 and 121.

FIGS. 4A-4C are schematic cross-sectional views of detachable treadcoupling 230 at different states, in accordance with some embodiments.Examples of different configurations of pins 235′ and cavities 235″controlled by interlocking mechanisms 235 are illustrated. As depictedin FIGS. 4A-4C, each protrusion (230-1, 230-2, 230-3, and 230-4)includes a pin 235′ located toward the base and a cavity 235″ locatedtoward the tip. Each pin 235′ and cavity 235″ are positioned such thatone pin 235′ is directly aligned with corresponding cavity 235″ whenfront tread portion 212 is fully paired with rear tread portion 214 asshown in FIGS. 4A and 4B. Each pin 235′ is controlled by oneinterlocking mechanism 235 including spring 236 and actuator 238. FIG.4A shows front tread portion 212 and rear tread portion 214 fully pairedand interlocked with springs 236 fully extended causing pins 235′ to beinserted and secured within cavities 235″. In various embodiments, thepins restrain the coupled tread portions and resist sheer forces indirections of the X and Z axes. The pins additionally prevent rotationalflex about the Y-axis. In other embodiments, multi-tread vehicle 200 mayinclude other support structures to increase the rigidness and stiffnessat detachable tread coupling 230. FIG. 4B shows front tread portion 212and rear tread portion 214 paired, but not fully interlocked withsprings 236 retracted and pins 235′ not inserted within cavities 235″.FIG. 4C shows the partial pairing of hermaphroditic coupling protrusionsof detachable tread couplings 230 a and 230 b.

In some embodiments, interlocking mechanisms 235 are electronicallyand/or wirelessly controlled. In some embodiments, interlockingmechanisms 235 are remotely controlled by an external user device. Thecontrol may be through other sections of multi-tread vehicle 200extending to the access opening or some other means (e.g., a tether),wireless communication link, and the like. As such, when a portion ofmulti-tread vehicle 200 needs to be removed from the operatingenvironment (e.g., to replace with another section, repair, maintenance,or simply upon completing of the operation). This features allows veryefficient use of multi-tread vehicle 200 in spaces with limited accessports. For example, pins 235′ may begin in a retracted state 235 a andare caused to extend by interlocking mechanisms 235 once the pins 235′are aligned with the corresponding cavities 235″ thereby moving intoprotracted state 235 b. As previously described, electrical power and/orcontrol signals, fiber optic control signals, pneumatic power and/orcontrol signals, and hydraulic power and/or control signals for suchoperations may be supplied through connectors 237. In another example,interlocking mechanisms 235 cause pins 235′ to retract until alignedwith the corresponding cavities 235″, at which point, interlockingmechanisms 235 cause pins 235′ to insert into aligned cavities 235″. Insome embodiments, first detachable tread coupling 230 a and seconddetachable tread coupling 230 b are remotely controlled using, forexample, a wire linkage 289 of connector section 280 that iselectrically coupled to an connector 237 (further described in FIG. 5B).In some embodiments, pins 235′ may alternatively, and/or additionally,function as power and data transfer mechanisms similar to 1 connectors237. In some embodiments, detachable couplings 230 and/or 270 may beactuated mechanically, e.g., by an operator when multi-tread vehicle 200is accessible, by another multi-tread vehicle 200 in the same operatingenvironment, and/or even by an end effector of the same multi-treadvehicle 200.

In various embodiments, connectors 237 at each protrusion allowelectrical, pneumatic, and/or hydraulic signals and/or power and/orfiber optic signals to be passed continuously along through eachconnected tread portions. In some embodiments, each connector 237 formsa male connector 237 a that inserts into a corresponding female receiversocket 237 b at the base of the protrusions, forming a male-femaleconnector configuration. Providing two connectors 237 on tread coupling230 may provide redundancy in case of failure or malfunction of oneconnector 237.

The electrical pneumatic, and/or hydraulic connection formed byconnectors 237 may power interlocking mechanisms 235 as well as supplyvarious control signals. For example, the successful insertion ofconnectors 237 into corresponding receiver sockets may allow flow ofelectrical pneumatic, and/or hydraulic power to signal interlockingmechanisms 235 to cause pins 235′ to insert into aligned cavities 235″.The electrical pneumatic, and/or hydraulic connection formed byconnectors 237 may also provide power to control various mechanisms,such as rotation of tread drives (such as 232 and 234), pivot drives(such as 242 and 244), as well as other mechanisms further describedbelow. In other embodiments, connectors 237 may additionally includeoptical fibers for data transfer.

Examples of Connection Sections

FIGS. 5A-5B are schematic views of connector section 280 of multi-treadvehicle 200, in accordance with some embodiments. As depicted, connectorsection 280 comprises front connector portion 282 and rear connectorportion 284. Front connector portion 282 comprises a part of detachableconnector coupling 270, front end 280′, front connector pivot coupling281, and front connector bend coupling 285. rear connector portion 284including another part of detachable connector coupling 270, rear end280″, rear connector pivot coupling 283, and rear connector bendcoupling 287.

Similar to tread portions 212 and 214, front connector portion 282 andrear connector portion 284 may be identical in geometry andconfiguration. As depicted in FIGS. 5A and 5B, front connector portion282 and rear connector portion 284 are identical structures rotated 180degrees relative to one another. In some embodiments, front connectorportion 282 is detachably coupled to rear connector portion 284 usingdetachable connector coupling 270. Parts of detachable connectorcoupling 270 may form hermaphroditic coupling structures similar toparts of tread coupling 230, and may include interlocking mechanismssimilar to interlocking mechanisms 235, described in FIGS. 4A-4C.Similar to some embodiments of tread section 210, detachable connectorcoupling 270 allow for assembly and disassembly of multi-tread vehicle200 for purposes of repairing failures or malfunctions of certaincomponents.

Various coupling portions of connector section 280 may providemechanisms for mobility and maneuverability of multi-tread vehicle 200.Front connector pivot coupling 281 may be centered around first rearpivot axis 293 a and couples to a rear tread pivot coupling, such asrear tread pivot coupling 213. Similarly, rear connector bend coupling283 is centered around second front pivot axis 291 b and couples to afront tread pivot coupling, such as front tread pivot coupling 211. Aspreviously described, pivot drives, such as 242 and 244, act onconnector pivot couplings, such as 281 and 283, to cause detachableconnector section 280 to rotate about pivot axes, such as 291 b and 293a.

Furthermore, front connector pivot coupling 281 of connector section 280may be bendable at front connector bend coupling 285 relative to rearconnector pivot coupling 283 of connector section 280 around front bendaxis 292. Front connector pivot coupling 281 of connector section 280may be further bendable at rear connector bend coupling 287 relative torear connector pivot coupling 283 around rear bend axis 294. In otherwords, connector section 280 may be bendable with respect to one or moreaxes.

In some embodiments, front connector bend drive 285′ may cause bendingof front end 280′ relative to rear end 280″ of connector section 280around front bend axis 292. Similarly, rear connector bend drive 287′may cause bending of front end 280″ relative to rear end 280′ ofconnector section 280 around rear bend axis 294.

FIG. 5B depicts a cross-sectional schematic view of connector section280 showing power (and/or signal) transmission linkage 289. As similarlinkage may be provided in each of tread section 210 and coupled totransmission linkage 289 either directly or through pivot coupling orother types of couplings between connector section 280 and tread section210. In other words, linkage 289 is a part of the overall power and/orsignal line extending through multi-tread vehicle 200. In someembodiments, power transmission linkage 289 comprises a suitable wiringmaterial with appropriate ratings for circuit voltage, temperature andenvironmental conditions (moisture, sunlight, oil, chemicals) in whichthey can be used, and maximum current. In some embodiments, powertransmission linkage 289 comprises an electrical wire or other materialcoupled to connector section 280. For example, power transmissionlinkage 289 comprises a conductive material embedded within connectorsection 280. In embodiments in which connector section 280 is detachableat connector coupling 270, power transmission linkage 289 may beseparated at connector coupling 270 and continued through by one or moreconnectors, such as connectors 237. Power transmission linkage 289 mayalso run continuously through connector bend couplings 285 and 287.

In some embodiments, power transmission linkage 289 is interconnected tofirst tread section 210 a and second tread section 210 b, andelectrically pneumatic, and/or hydraulic coupled to connectors 237either directly (e.g., using a permanent connector) or through pivotcoupling between tread sections 210 and connector section 280. It shouldbe noted that even a direct connection to power transmission linkage 289may allow tread sections 210 and connector section 280 to pivot withrespect to each other when the connection uses, for example, a flexibleline having a sufficient length allow for pivoting. At the same time,linkage 289 may be separable at detachable connector coupling 270. Insome embodiments, tread portions 212 and 214 of tread section 210 alsoinclude a similar power transmission linkage connecting to connectors237 to power various elements of tread section 210.

Power transmission linkage 289 may be responsible for transmittingelectrical power and/or control signal from a power source throughmulti-tread vehicle 200 in order to power various elements on each treadand connector section, such as connector bend drives 285′ and 287′,tread drives 232 and 234, pivot drives 242 and 244, and interlockingmechanisms 235. In other embodiments, various other systems can berouted through each tread section 210 and connector section 280 of amulti-tread vehicle 200. For example, hoses can be routed through suchthat air can be pumped into the wing or sucked out. As another example,hydraulic lines can be routed through one or more tread sections 210 andconnector sections 280. In other embodiments, power transmission linkage289 may additionally include an optical fiber for data transfer.However, in some embodiments, the many joints created by the variouscouplings create an increased chance for failure or damage to variousrouted pipes, hoses, and/or lines. Thus, in some embodiments, it may bedesirable to route only electrical power through electrical wiring andconnectors 237 in order to power wireless devices, air pumps, orhydraulic pumps that have been transported into the wing.

Articulation Examples

FIGS. 6A-6C are schematic top views of multi-tread vehicle 200 duringdifferent folding states, in accordance with some embodiments.Specifically, FIG. 6A depicts multi-tread vehicle 200 in folded state600. FIG. 6B depicts multi-tread vehicle 200 in partially folded state605. Finally, FIG. 6C depicts multi-tread vehicle 200 in extended state610. According to various embodiments, multi-tread vehicle 200 isfoldable between folded state 600 and extended state 610. The folding offirst tread section 210 a, second tread section 210 b, and connectorsection 280 is coordinated pivoting around first rear pivot axis 293 aand around the second front pivot axis 291 b. As previously described,such rotation may be controlled by one or more pivot drives located ontread section 210, such as front pivot drive 242 and rear pivot drive244. The rotation of connector section 280 around first rear pivot axis293 a and second front pivot axis 291 b may or may not be simultaneous.

In folded state 600 of certain embodiments, first front left tread 224 ais disposed between first front right tread 222 a and second front righttread 222 b, as depicted in FIG. 6A. Furthermore, first front left tread224 a is adjacent to and parallel to second front right tread 222 b.Similarly, first rear left tread 228 a may be disposed between firstrear right tread 226 a and second rear right tread 226 b. First rearleft tread 228 a may be adjacent and parallel to second rear right tread226 b.

In extended state 610, a plurality of treads may be collinearly aligned.For example, first front right tread 222 a and second front right tread222 b may be collinear in extended state 610. Additionally, first rearright tread 226 a and second rear right tread 226 b may also becollinear with first front right tread 222 a and second front righttread 222 b. Finally, first front left tread 224 a, second front lefttread 224 b, first rear left tread 228 a, and second rear left tread 228b may all collinear in extended state 610 of multi-tread vehicle 200.

FIG. 6B depicts partially folded state 605 of multi-tread vehicle 200illustrating transition from folded state 600 to extended state 610, orvice versa. As shown in FIG. 6B, multi-tread vehicle 200 may be causedto extend into extended state 610 from folded state 600 by the rotationof connector section 280 around first rear pivot axis 293 a in thecounterclockwise direction A and by the rotation of connector section280 around second front pivot axis 291 b in the counterclockwisedirection A until first front right tread 222 a and second front righttread 222 b are collinear, as described above.

As further depicted in FIG. 6B, multi-tread vehicle 200 may be caused tofold into folded state 600 from extended state 610 by pivoting connectorsection 280 relative to tread sections 210 a and 210 b around first rearpivot axis 293 a in the clockwise direction B and around second frontpivot axis 291 b in the clockwise direction B. Alternatively, and oradditionally, connector section 280 may cause the folding of multi-treadvehicle 200 from extended state 610 by pivoting around first rear pivotaxis 293 a and second front pivot axis 291 b in the counterclockwisedirection A. In such an embodiment, multi-tread vehicle will be foldedsuch that second front left tread 224 b is disposed between second frontright tread 222 b and first front right tread 222 a (not shown).Furthermore, in such this example of folded state 600, second front lefttread 224 b is adjacent to and parallel to first front right tread 222a.

FIG. 6D is a schematic top view of multi-tread vehicle in folded state600 showing different dimensions, in accordance with some embodiments.As previously described, first front portion 212 a may include firstfront pivot axis 291 a and first rear portion 214 a may include firstrear pivot axis 293 a. Furthermore, second front tread portion 212 b mayinclude second front pivot axis 291 b and second rear portion 214 b mayinclude second rear pivot axis 293 b. In folded state 600, distance 293′between first rear pivot axis 293 a and second front pivot axis 291 bmay be equal to the square root of the sum of the square of distance293″ between first front pivot axis 291 a and first rear pivot axis 293a and square of distance 291′ between first front pivot axis 291 a andsecond front pivot axis 291 b, as given by the following equation:293′=√{square root over ((293″)²+(291′)²)}

In some embodiments, distance 293′ is equal to the distance betweenfirst front pivot axis 291 a and second rear pivot axis 293 b, anddistance 291′ between first front pivot axis 291 a and second frontpivot axis 291 b is equal to a width of first tread section 210 a. Asdepicted in FIG. 6D, distance 291′ is equal to the combined distance ofhalf-width 210 a′ and half width 210 b′, where half width 210 a′represents half of the width of first tread section 210 a from itscenter to the outer edge of first front left tread 224 a, and half width210 b′ represents half the width of second tread section 210 b from itscenter to the outer edge of second front right tread 222 b. In FIG. 6D,half width 210 a′ and half width 210 b′ may be equal in measurement.This configuration may cause first front left tread 224 a to rest flushagainst the adjacent second front right tread 222 b when multi-treadvehicle 200 is in folded state 600. In other embodiments, there may be agap of varying size first front left tread 224 a and second front righttread 222 b when multi-tread vehicle 200 is in folded state 600. In someembodiments, the widths of all tread sections, including first treadsection 210 a and second tread section 210 b, are equal in measurement.In other embodiments, the width of tread sections, such as 210 a andtread section 210 b, may vary.

In various embodiments, it may be desirable for the length of a treadsection, such as first tread section 210 a, to be at least greater thanthe distance between supporting structures. With such a configuration,multi-tread vehicle 200 including first tread section 210 a and secondtread section 210 b coupled by a connector section 280 traveling throughan opening 124 along interior operating paths space 126 b within a wing120 may be supported by the lower edge 125 of at least two ribs 122, andat most four ribs 122, at all times. In an example, a wing baycompartment of interior 126 may be approximately 2 feet from rib to rib,such as from rib 122 a to rib 122 b. The length of a tread section 210 amay be approximately 30 inches long in order to span from rib 122 a torib 122 b. In another example, the width of a tread section 210 may beapproximately 12 inches and the height of multi-tread vehicle may beapproximately 6 inches high. In some embodiments, tread section 210 maybe shorter than the distance of between supporting structure and may besupported by other tread sections 210 (through connector section 280)that contact supporting structures.

In various embodiments, it may be desirable to achieve the smallestrectangular profile as possible for multi-tread vehicle 200, taking intoaccount the size of tools and other components to be carried into wing120 by multi-tread vehicle 200, in order to limit the size of openings124 and ports leading into interior 126 of wings 120 and/or 121. It maybe desirable for tread section 210 to be as narrow as possible in widthand a short as possible in height. Smaller openings 124 may result inmore structurally sound support structures such as ribs 122. In otherembodiments, multi-tread vehicle 200 is sized to fit within openings 124and along wing bay compartment of interior 126, which may vary in lengthand size among various embodiments.

FIGS. 6E and 6F are schematic top views of a multi-tread vehicle havingmultiple tread and connector sections, in accordance with someembodiments. Additional tread sections 210, such as tread sections 210 cand 210 d, may be coupled to multi-tread vehicle 200 with additionalconnector sections 280, such as connector sections 280 b and 280 c. Insome embodiments, tread sections 210 a, 210 b, 210 c, and 210 d areidentical units. In some embodiments, connector sections 280 a, 280 b,and 280 c are identical units. As shown in FIGS. 6E and 6F, multi-treadvehicle 200 includes first tread section 210 a coupled to second treadsection 210 b by a first connector section 280 a, third tread section210 c coupled to second tread section 210 b by second connector section280 b, and fourth tread section 210 d coupled to third tread section 210c by third connector section 280 c. FIG. 6E depicts multi-tread vehicle200 with additional tread sections 210 and connector sections 280 in afolded state 600. FIG. 6F depicts multi-tread vehicle 200 withadditional tread sections 210 and connector sections 280 in a partiallyfolded state 605, with first tread section 210 a and second treadsection 210 b completely folded and tread sections 210 c and 210 dpartially extended.

In some embodiments, the folding of multi-tread vehicle 200 provides forcompact storage of multi-tread vehicle 200. In some embodiments, wing120 or 121 of aircraft 100 may be as long as 200 feet or more. Amulti-tread vehicle 200 may comprise enough tread sections 210 andconnector section 280 to span the entire length of wing 120 or 121.Without such folding capabilities, would take a significant amount ofspace to store such a long multi-tread vehicle 200, and even more spaceto operate a non-folding multi-tread vehicle 200 in conjunction withwing 120 and/or 121.

FIG. 7A is a schematic side view of multi-tread vehicle 200 showingbending of connector sections 280 of multi-tread vehicle 200, inaccordance with some embodiments. FIG. 7A depicts a multi-tread vehicle200 with first connector section 280 a coupled to first tread section210 a and second tread section 210 b, and second connector section 280 bcoupled to second tread section 210 b and third tread section 210 c.Connector sections 280 a and 280 b are examples of connector section 280previously detailed in FIGS. 5A-5B. In the present example, firstconnector section 280 a includes a front end 280 a′, a rear end 280 a″,front connector bend coupling 285 a, rear connector bend coupling 287 a,front bend axis 292 a, rear bend axis 294 a. Additionally, secondconnector section 280 b includes front end 280 b′, rear end 280 b″,front connector bend coupling 285 b, rear connector bend coupling 287 b,second front bend axis 292 b, and second rear bend axis 294 b. A firstplane 290 a may be defined by first rear right tread 226 a and firstrear left tread 228 a of first tread section 210 a, as previouslydescribed in FIGS. 2A-2B. A second plane 290 b may be similarly definedby second front right tread 222 b and second front left tread 224 b ofsecond tread section 210 b, as previously described. Additionally, athird plane 290 c is similarly defined by the corresponding treads ofthird tread section 210 c and is parallel to first plane 290 a andsecond plane 290 b as shown in FIG. 7A.

As previously described in FIG. 5A, in some embodiments, connectorsection 280, such as first connector section 280 a, includes frontconnector bend coupling 285, such as front connector bend coupling 285a, centered around front bend axis 292, such as first front bend axis292 a, and rear connector bend coupling 287, such as rear connector bendcoupling 287 a centered around a rear bend axis, such as first rear bendaxis 294 a, at which connector section 280 and/or 280 a may bend. Invarious embodiments, a front end 280 a′ of a connector section 280 a canbend relative to rear end 280 a″ at front connector bend coupling 285 a.In some embodiments, front bend axis 292 a is parallel to plane 290 a.Front end 280′ of first connector section 280 a may be further bendablerelative to rear end 280 a″ of connector section 280 a around rear bendaxis 294 a. In some embodiments, rear bend axis 294 a is parallel toplane 290 a.

Second connector 280 b includes a similar configuration to firstconnector 280 a. Second connector section 280 b includes second frontconnector bend coupling 285 b centered around second front bend axis 292b, and second rear connector bend coupling 287 b centered around rearbend axis 294 b, at which second connector section 280 b may bend. Invarious embodiments, front end 280 b′ of connector section 280 b canbend relative to rear end 280 b″ at front connector bend coupling 285 b.In some embodiments, front bend axis 292 b is parallel to plane 290 b.Front end 280 b′ of second connector section 280 b may be furtherbendable relative to rear end 280 b″ of connector section 280 b around arear bend axis 294 b. In some embodiments, rear bend axis 294 b isparallel to plane 290 b.

In various embodiments, first connector section 280 a can be configuredto allow bending at various angles of front end 280 a′ relative to rearend 280 a″ allowing planes 290 a, 290 b, and 290 c to be configured atdifferent angles relative to one another. In some embodiments, secondconnector section 280 b is configured to have similar bendingcapabilities as first connector section 280 a. In various embodiments,the bending of each connector section, 280 a and 280 b, around thevarious bend axes (292 a, 294 a, 292 b, and 294 b) allow the multi-treadvehicle 200 to achieve a staggered configuration of tread sections 210a, 210 b, and 210 c, as shown in FIG. 7A. As shown in FIG. 7A, the firstplane 290 a, second plane 290 b, and third plane 290 c are parallel. Insome embodiments, bending of connector sections 280 a and 280 b allows atread section, such as second tread section 210 b, to rest on the bottomsurface of a wing bay compartment of a wing 120 for additional supportand/or increase access for repairs and maintenance.

Bending of connector sections 280 a and 280 b may also allow folding ofmulti-tread vehicle 200 such that tread sections 210 a, 210 b, and 210 care stacked on the top of each other, as, for example, shown in FIG. 7B.This vertical stacking arrangement may be used during storage ofmulti-tread vehicle 200 detaching portions of connector sections 280 aand 280 b and/or tread sections 210 a, 210 b, and 210 c. This verticalstacking may be used as an alternative or in addition to horizontalfolding described above with reference to FIGS. 6A-6F.

Furthermore, bending of connector sections 280 a and 280 b may alsoallow folding of multi-tread vehicle 200 to be deployed through accessports that may be not be within the plane of the vehicle path. Forexample, as shown in FIG. 7C, multi-tread vehicle 200 may be deployedthrough lower wing skin panel 127 of wing 120 or, more specifically,through access port 129 within lower wing skin panel 127. As such,multi-tread vehicle 200 may not need to travel through entire width orlength of wing 120 in, order for example, to reach the most remoteportion of wing 120.

As shown in FIG. 7C, multi-tread vehicle 200 may be vertically stackedoutside of wing 120. Stack 201 may be disposed within storage 700.During the deployment, storage 700 containing stack 201 formed by foldedmulti-tread vehicle 200 may be positioned next to access port 129 withinlower wing skin panel 127. Multi-tread vehicle 200 may be unfoldedsection by section and deployed into interior 126 of wing 120.Multi-tread vehicle 200 may be unfolded into a planar orientation withinwing 120 and extend in this planar orientation to operating zone 128which may be remotely positioned from access port 129. The support tomulti-tread vehicle 200 may be provided by ribs 122 or some otherstructures. It should be noted that bending of connector sections 280may also allow tread sections 210 deviate from the planar orientationand, for example, to reach wing skin portion 127 as, for example, shownin FIG. 7C. This contact with wing skin portion 127 may be used forsupport, performing some operations on wing skin portion 127, and/orother purposes.

FIG. 7D illustrates another example of deploying multi-tread vehicle 200through access port 129 within lower wing skin panel 127. In thisexample, multi-tread vehicle 200 includes tread sections 210, eachhaving only one tread portion 212. This configuration may be used toachieve more articulation since tread sections 210 may be more compact.Of course, using one tread portion may not allow for separatingmulti-tread vehicle 200 at tread sections 210. Instead connectorsections 280 may be used for this purpose.

Furthermore, the deployment of multi-tread vehicle 200 in FIG. 7D isperformed in a different direction (i.e., in the Y direction) withinwing than the deployment direction presented in FIG. 7C. One havingordinary skill in the art would understand that multi-tread vehicle 200may be deployed in any direction. FIG. 7C also illustrate tool 906 andsensor 904 (e.g., camera, microphone, and the like) supported by firstconnector section 280. Tool 906 and sensor 904 are further describedbelow with reference to FIG. 9. It should be noted that tool 906 and/orsensor 904 may be connected directly to one section of multi-treadvehicle 200 or to an end effector.

FIG. 7E illustrates yet another example of deploying multi-tread vehicle200 through access port 129 within lower wing skin panel 127. In thisexample, multi-tread vehicle 200 include one tread section 210 connectedby tether 1106 to base station 702 of storage 700. Examples of tether1106 and operations using tether 1106 are described below with referenceto FIG. 11. Base station 702 may be in turn connected to a system forcontrolling multi-tread vehicle 200. In this example, storage 700 mayalso include ramp 701 extending to access port 129 since tread section210 does not have any other sections for support when reaching accessport 129.

In some embodiments, the materials used to manufacture multi-treadvehicle 200 provide stiffness and rigidness to tread sections, connectorsections, and the corresponding couplings, allowing multi-tread vehicle200 to span significant distances without sagging or compromising theparallel configuration of planes 290 a, 290 b, and 290 c. This may allowmulti-tread vehicle 200 to remain aligned with each opening 124. In someembodiments, gravity may cause the front end of multi-tread vehicle 200to dip a certain amount, at which point multi-tread vehicle 200 may relyon rotation of the treads to climb over an edge 125 of an opening 124.There may be instances in which a multi-tread vehicle dips to a certaindegree that it becomes misaligned with an opening 124. Bending ofconnector sections 280 a and 280 b may allow upward and downwardadjustments to ensure that tread sections 210 a, 210 b, and 210 c alignwith openings 124 as the multi-tread vehicle 200 travels throughinterior operating paths 126 a, 126 b, or 126 c.

FIGS. 8A and 8B are schematic top and side views of a multi-treadvehicle showing a combination of bending and pivoting, in accordancewith some embodiments. An alternative configuration of tread sectionsand connector sections are depicted in FIGS. 8A-8B. First tread section210 a is coupled to second tread section 210 b by first connectorsection 280 a. Third tread section 210 c is coupled to second treadsection 210 b by second connector section 280 b. Fourth tread section210 d is coupled to third tread section 210 c by third connector section280 c.

First plane 290 a is defined by support points of the treads on firsttread section 210 a, as previously described in FIGS. 2A-2B. A portionof first plane 290 a is outlined by a dashed line in FIG. 8A. The bottomsurfaces of treads on each of the other tread sections similarly definethe other corresponding planes 290 b, 290 c, and 290 d. Second plane 290b is defined by the support points of the treads on second tread section210 b. Third plane 290 c is defined by the support points of the treadson third tread section 210 c. Fourth plane 290 d is defined by thesupport points of the treads on fourth tread section 210 d. Firstconnector section 280 a rotates about a first pivot axis 291 aperpendicular to first plane 290 a, and bends about a first bend axis292 a parallel to first plane 290 a. Second connector section 280 brotates about a second pivot axis 291 b perpendicular to second plane290 b, and bends about a second bend axis 292 b parallel to second plane290 b. Third connector section 280 c rotates about a third pivot axis291 c perpendicular to third plane 290 c, and bends about a third bendaxis 292 c parallel to third plane 290 c.

In FIGS. 8A-8B, first tread section 210 a and first plane 290 a arepositioned horizontally in parallel to a plane defined by the X and Yaxes. First connector section 280 a is bent about first bend axis 292 ain direction F such that second tread section 210 b and second plane 290b are diagonal and angled downward relative to first tread section 210 aand first plane 290 a. Second connector section 280 b is further bentaround second bend axis 292 b in direction E such that third treadsection 210 c and third plane 290 c are angled upward relative to secondtread section 210 b and second plane 290 b. As shown in FIG. 8B, thirdtread section 210 c and third plane 290 c are positioned horizontally inparallel to first plane 290 a and a plane defined by the X and Y axes.Third connector section 280 c is not bent about third bend axis 292 c sothat fourth tread section 210 d and fourth plane 290 d are also parallelto first plane 290 a and a plane defined by the X and Y axes.

As shown in FIG. 8A, first tread section 210 a and second tread section210 b are aligned along the Y-axis. Second connector section 280 b isfurther rotated about second pivot axis 291 b in direction D such thatthird tread section 210 c is angled relative to first tread section 210a and second tread section 210 b. Third connector section 280 c is alsorotated about third pivot axis 291 c in direction C such that fourthtread section 210 d is angled relative to third tread section 210 c andparallel to first tread section 210 a and second tread section 210 b. Incertain embodiments, such maneuverability about pivot axes and bend axesallow multi-tread vehicle 200 to access multiple surfaces within a wingbay compartment within interior 126 of wing 120.

Depending on the number of different articulations, multi-tread vehicle200 may be used as a highly-articulated end-effector arm, which may ormay not be attached to another multi-tread vehicle 200. For example,first multi-tread vehicle 200 may have sections that are smaller in sizeand have more articulation options than second multi-tread vehicle 200.Second multi-tread vehicle 200 may be used as a carrier/transport forfirst multi-tread vehicle 200, which in turn is used to perform variousfunctions within an operating environment, either directly or through aset of sensors and manipulators.

Examples of Sensors and Tools

FIG. 9 is a schematic side view of multi-tread vehicle 200 showingdifferent sensors, cameras, and lights of multi-tread vehicle 200, inaccordance with some embodiments. In various embodiments, multi-treadvehicle 200 further comprises proximity sensors, cameras, lights, andother components to enable navigation through interior 126 of wings 120and 121. FIG. 9 depicts a longitudinal cross-section of a wing 120 fromthe C-C viewpoint (identified in FIG. 1A) corresponding to thelongitudinal Y-axis, as described in FIGS. 1A-IC. FIG. 9 further shows amulti-tread vehicle 200 traveling through openings 124 of ribs 122 b and122 c and supported by the lower edge 125 of rib 122 b. Tread section210 may be coupled to other tread sections, such as tread section 210 band 210 c by first connector section 280 a and second connector section280 b. In some embodiments, multi-tread vehicle 200 includes light 901 alocated on the top surface of first connector section 280 a and light901 b located on bottom surface of tread section 210. Multi-treadvehicle further includes camera 902 a located on the top surface oftread section 210 and camera 902 b located on the bottom surface oftread section 210. Multi-tread vehicle 200 further includes sensor 904 alocated on second connector section 280 b, and sensors 904 b and 904 clocated on tread section 210. In various embodiments, such componentsmay be located on different portions of multi-tread vehicle 200. Inother embodiments, a multi-tread vehicle 200 may include more or fewerinstances of the components as shown in FIG. 9.

In various embodiments, cameras 902 a and 902 b include any type ofvideo or image capturing device that captures images and/or video. Insome embodiments, the video may be a streaming real-time video feed.Such devices may include geometrically-correct stereoscopic camera pairsthat provide depth perception and/or binocular stereopsis. Imagescapture by cameras 902 a and 902 b are used in navigating multi-treadvehicle 200 through various openings 124 in ribs 122. For example,captured images may show that multi-tread vehicle 200 may not bepositioned adequately to enter into an approaching opening 124 becauseit is too low. In other embodiments, images captured by cameras 902 aand 902 b are used to visually inspect interior space 126 and/or variousobjects within interior space 126 of wing 120. Captured images may alsobe used to visually identify malfunctions of multi-tread vehicle 200. Insome embodiments, capture images may be used to visually identifymalfunctions of a separate multi-tread vehicle 200.

In some embodiments, cameras 902 a and 902 b provide a wide angle viewof interior 126. In other embodiments cameras 902 a and 902 b can beadjusted and directed to capture images from different locations. Insome embodiments, lights 901 a and 901 b provide lighting for imagescaptured by cameras 902 a and 902 b. In various embodiments, lights 901a and 901 b may comprise various lighting sources, including but notlimited to LED and halogen lights. In some embodiments, lights 901 a and901 b can be adjusted to increase or decrease brightness, as well aspositioned to focus light on particular areas of interest. In someembodiments, cameras and lights are positioned at tips of tread sections210 and connector sections 280. In other embodiments, cameras and lightsmay be positioned at various other locations on multi-tread vehicle 200.

In various embodiments, sensors 904 a, 904 b, and 904 c are proximitysensors that can detect the presence of nearby objects without anyphysical contact. In some embodiments, such proximity sensors mayoperate by emitting an electromagnetic field or a beam ofelectromagnetic radiation, such as infrared, in order to detect changesin the field or return signal. In other embodiments, other mechanismsmay be implemented by sensors 904 a, 904 b, and 904 c, such as laserrangefinders, passive optical, radar, sonar, etc. For example, sensor904 c may detect the proximity of multi-tread vehicle 200 to bottom edge125 of rib 122 c. If the proximity is too close, sensor 904 c mayactivate a signal warning the operator of multi-tread vehicle 200. Inanother embodiment, sensor 904 c may prohibit any additional movementthat may cause multi-tread vehicle 200 to collide with rib 122 c. Invarious embodiments, information captured by cameras and sensors aretransmitted wirelessly to a user device and/or via optical fibers.

FIG. 9 also illustrates tool 906 for performing various operations. Someexamples of tool 906 include, but are not limited, to a drill, a sealer,a brush, an punch, a wrench, and the like. Tool 906 may be operatedeither directly and/or by various manipulations of multi-tread vehicle200.

FIG. 9 also illustrates end effector 900 of multi-tread vehicle 200,which may be attached to tread section 210 (as shown) or to connectorsections 280. In some embodiments, end effector 900 is multi-treadvehicle 200 itself, which may have smaller tread sections and connectorsections. End effector 900 may be more articulated than multi-treadvehicle 200 supporting this end effector 900. The supporting multi-treadvehicle 200 may be referred to as a delivery vehicle, transport vehicle,and the like. In some embodiments, end effector 900 includes sensors,manipulators, lights, and the like.

Processing Examples of Using Multi-Tread Vehicles

FIG. 10 is a process flowchart corresponding to a method 1000 foraccessing an interior space using a multi-tread vehicle, in accordancewith some embodiments. In various embodiments, method 1000 isimplemented to access interior 126 of aircraft 100 using multi-treadvehicle 200. Dashed lines within FIG. 10 indicate optional operationsand/or components to method 1000.

At operation 1002, a tread section and a connector section areinterconnected. As described in previous figures, in some embodiments,multi-tread vehicle 200 comprises first tread section 210 a, secondtread section 210 b, and connector section 280 coupled to first reartread portion 214 a and to second front tread section 212 b. In someembodiments, multi-tread vehicle 200 comprises additional tread sectionsand connector sections. In some embodiments, a front connector pivotcoupling 281 is coupled to a rear tread pivot coupling 213 of a firstrear tread portion 214 a. Furthermore, a rear connector pivot coupling283 is coupled to a front tread pivot coupling 211 of a second fronttread portion 212 b. In some embodiments, the interconnection of treadsections 210 a and 210 b with connector section 280 cause electricalpower to be transported through the entire multi-tread vehicle 200 viapower transmission linkages 289 and connectors 237, previously describedin FIGS. 3A-3C and 5A-5B.

At operation 1004, multi-tread vehicle 200 is positioned at an opening124 to interior space 126 of aircraft 100. In some embodiments,multi-tread vehicle 200 may access interior 126 through opening 124 intowing 120 located on bulkhead rib 122 a at inboard end 120 c of wing 120,however, other access ports are also within the scope. For example, theaccess port may be located within outboard end of wing, lower or upperwing skin panel, front or rear spar, and the like. In other embodiments,multi-tread vehicle 200 may access interior 126 through an opening 124into wing 120 located at outboard end 120 d of wing 120.

At operation 1010, first tread section 210 a is advanced into interiorspace 126. In some embodiments, first tread section 210 a may includevarious end effectors comprising sensors and/or manipulators (e.g., ahighly articulated arm), which advanced first. In some embodiments,method 1000 comprises advancing at least first tread section 210 a ofmulti-tread vehicle 200 into the opening 124 that multi-tread vehicle200 was positioned to at operation 1004. Advancing tread section 210 ainto opening 124 may include operating a driving motor at operation1012, such as front tread drive 232. In some embodiments, operation offront tread drive 232 causes rotation of first front right tread 222 aand first front left tread 224 a while first front right tread 222 a andfirst front left tread 224 a contact a portion of an edge 125 definingopening 124 of a rib, such as rib 122 a. The contacting treads may thengrip edge of rib 122 a to propel multi-tread vehicle 200 into opening124 and into interior 126 of wing 120. Multi-tread vehicle 200 maycontinue advancing along one or more ribs 122 along interior operatingpath 126 c defined by one or more aligned openings 124 as described inFIG. 1C. operation 1010 may include additionally and/or alternativelyoperating rear tread drive 234 of first tread section 210 a to causerotation of first rear right tread 226 a and first rear left tread 228 awhile first rear right tread 226 a and first rear left tread 228 acontact a portion of an edge 125. In some embodiments, operation 1010includes additionally and/or alternatively operating front tread derive232 and/or rear tread drive 234 of second tread section 210 b.

In some embodiments, first tread section 210 a and connector section 280are collinear while advancing first tread section 210 a. Second treadsection 210 b may also be collinear with first tread section 210 a andconnector section 280 while advancing first tread section 210 a. In someembodiments, first tread section 210 a is simultaneously supported by atleast two edges 125 for at least a period of time while advancing firsttread section 210 a.

In some embodiments, multi-tread vehicle 200 is further advanced throughone or more aligned openings in subsequent ribs, such as ribs 122 b and122 c. As previously described, multi-tread vehicle 200 may besimultaneously supported by at least two edges 125 for at least a periodof time while advancing into wing bay compartments through openings 124.For example, first tread section 210 a and second tread section 210 bmay each be simultaneously supported by an edge 125 of two or more ribs.In some embodiments, multi-tread vehicle 200 may be advanced throughopenings 124 from inboard end 120 c of wing 120 to outboard end 120 d ofwing 120, or vice versa.

At operation 1020, a tread section is pivoted relative to a connectorsection. In some embodiments, pivoting tread sections, such as 210 aand/or 210 b, at operation 1020 involves the pivoting motions describedin FIGS. 8A-8B. For example, first tread section 210 a is pivoted aboutfirst rear pivot axis 293 a. In another example, second tread section210 b may be pivoted about second front pivot axis 291 b. In someembodiments, pivoting first tread section 210 a may be performed whileboth first tread section 210 a and connector section 280 are positionedwithin interior space 126. Pivoting first tread section 210 a and/or 210b may also be performed while any combination of the following arepositioned within and/or outside interior 126: first tread section 210a, second tread section 210 b, and connector section 280. In someembodiments, pivoting tread sections 210 a and/or 210 b includesoperating a pivot drive, such as front pivot drive 242 or rear pivotdrive 244 (as described in FIG. 3B), at operation 1022. In someembodiments, tread section 210 a and/or tread section 210 b may bepivoted relative to connector section 280 while advancing tread section210 a and/or tread section 210 b into interior 126. In some embodiments,the pivoting of multi-tread vehicle 200 at operation 1020 enablesmulti-tread vehicle 200 to access various portions of a wing baycompartment of interior space 126.

At operation 1030, connector section 280 is bent. In some embodiments,bending connector section 280 at operation 1030 involves the bendingmotions described in FIGS. 8A-8B. For example, connector section 280 isbent about a bend axis, such as front bend axis 292 or rear bend axis294. In some embodiments, bending connector section 280 may be performedwhile both first tread section 210 a and connector section 280 arepositioned within interior space 126. In further embodiments, bendingconnector section 280 may be performed while any combination of thefollowing are positioned within and/or outside of interior 126: firsttread section 210 a, second tread section 210 b, and connector section280. In some embodiments, connector section 280 includes operating abend drive at operation 1032. For example, the bend drive may be frontconnector bend drive 285′ for bending front end 280′ of connectorsection 280 relative to rear end 280″ at front bend axis 292. In anotherexample, the bend drive is rear connector bend drive 287′ for bendingrear end 280″ of connector section 280 relative to front end 280′ atrear bend axis 294. In some embodiments, the bending of multi-treadvehicle 200 at operation 1030 enables multi-tread vehicle 200 to accessvarious portions of a wing bay compartment of interior space 126. Insome embodiments, connector section 280 may be bent while advancingtread section 210 a and/or tread section 210 b into interior space 126.

At operation 1040, an image of interior 126 is captured. In someembodiments, an image is captured by camera 902 a and/or camera 902 bdescribed in FIG. 9. At operation 1050, one or more operations areperformed within interior 126. In various embodiments, operationsinclude various interior wing tasks including maintenance, repair,and/or inspection procedures. Performing operations may includeoperating a highly-articulated arm within interior 126 at operation1052. In some embodiments, a highly articulated arm includes an endeffector that can be equipped to transport various tools and/or sensors,or to manipulate various parts and/or components to conduct interiorwing tasks, such as maintenance, inspection and/or repairs, withininterior space 126 of wing 120.

At operation 1060, a tread section, such as first tread section 210 a,is advanced from interior space 126. In some embodiments, advancingtread section 210 a from interior space 126 includes operating a drivingmotor at operation 1062. In some embodiments, operation 1062 includesthe same and/or similar operations as operation 1012, as previouslydescribed. For example, operation 1062 may include activating fronttread drive 232 and/or rear tread drive 234 of first tread section 210 aand/or second tread section 210 b to rotate in an opposite direction asthat in operation 1010 in order to advance multi-tread vehicle in anopposite direction as that in operation 1010, in order to causemulti-tread vehicle 200 to exit interior 126.

In various embodiments, pivoting first tread section 210 a at operation1020 and bending connector section 280 at operation 1030 may besimultaneous or at least partially overlap in time. Operations 1020 and1030 may also occur simultaneously or at least partially overlap in timewith advancing first tread section 210 a at operation 1010 and/oroperation 1060. In some embodiments, operations 1040 and 1050 may alsooccur simultaneously or at least partially overlap in time withadvancing first tread section 210 a at operation 1010 and/or operation1060.

FIGS. 11A-11D are schematic views of multi-tread vehicles withininterior spaces at different stages of method 1000, in accordance withsome embodiments. FIGS. 11A-11D depict wing 120 also described in FIGS.1A-IC. FIGS. 11A, 11C, and 11D illustrate a horizontal cross-section ofwing 120 from the B-B viewpoint (identified in FIG. 1A) corresponding tothe vertical axis (Z-axis) described in FIGS. 1A and 1C. FIG. 11Bdepicts a longitudinal cross-section of wing 120 from the C-C viewpoint(identified in FIG. 1A) corresponding to the longitudinal axis (Y-axis)described in FIGS. 1A-1C. As shown in FIGS. 11A-11D, wing 120 is definedby a leading edge 120 a, a trailing edge 120 b, an inboard end 120 c,and an outboard end 120 d. Wing 120 further includes eight ribs 122defining wing bay compartments, including rib 122 a, which lies oninboard end 120 c, and ribs 122 b, 122 c, 122 d, 122 e, 122 f, 122 g,and 122 h. As previously described in FIGS. 1A-IC, each of the ribsinclude one or more aligned openings 124 that define one or moreinternal operating paths of interior 126, including interior operatingpaths 126 a, 126 b, and 126 c.

FIG. 11A shows three multi-tread vehicles 200 deployed within wing 120.Multi-tread vehicles 200 a, 200 b, and 200 c deployed through openings124 of rib 122 a at inboard end 120 c of wing 120, such as described inoperation 1004. Other access openings may be provided within lowerand/or upper wing skin panels that, in some embodiments, may besubstantially parallel to the X-Y plane. When access through the skipportion openings, multi-tread vehicle 200 may have bending capabilitiesas, described above, with reference to FIGS. 7A-7C and 8B. In thisexample, the access direction may be at an angle (e.g., at a rightangle) to the main advancing direction within wing 120. Multi-treadvehicle 200 a has advanced within internal operating path 126 a, as inoperation 1010. Multi-tread vehicle 200 a comprises one tread section,such as tread section 210, and connection point 1104 a. Multi-treadvehicle 200 b has also advanced within internal operating path 126 b,such as in operation 1010. Multi-tread vehicle 200 b comprises threetread sections, such as tread section 210, coupled to two connectorsections, such as connector section 280, and was interconnected asdescribed in operation 1002. Multi-tread vehicle 200 b further comprisesconnection point 1104 b. Multi-tread vehicle 200 c has also advancedwithin interior operating path 126 c, as in operation 1010. Multi-treadvehicle 200 c comprises four tread sections, such as tread section 210,coupled to three connector sections, such as connector section 280, andwas interconnected as described in operation 1002. Multi-tread vehicle200 c further comprises connection point 1104 c. Various portions ofmulti-tread vehicles 200 b and 200 c outside of wing 120 are shownpivoting around pivoting axes in FIG. 11A, such as in operation 1020.

In various embodiments, connection points 1104 a, 1004 b, and 1104 c maycouple to various different components, including highly articulatedeffector arms, end effector mechanisms, tools, cameras, lighting, etc.As previously described, multi-tread vehicles 200 a, 200 b, and 200 cmay be utilized to advance components coupled to connection points 1104a, 1104 b, and 1104 c into a desired location within wing 120 in orderto conduct various internal wing tasks including inspection,maintenance, repair, etc., utilizing remote end effectors, such as inoperation 1040 and 1050. Such internal wing tasks may additionallycomprise drilling, fastening, sealing, cleaning, gauging, painting, etc.Multiple interior operating paths 126 a, 126 b, and 126 c providemultiple parallel paths allow simultaneous performance of tasks.Multiple parallel paths also allow for servicing or removal of a jammedor broken components and/or portions of multi-tread vehicle 200, such as200 a, by another multi-tread vehicle, such as 200 b.

FIG. 11B illustrates an alternative view showing multi-tread vehicle 200c within wing 120. The portions of multi-tread vehicle 200 c that arelocated at the exterior of wing 120 may rest on platform 1102 as thevarious sections are advanced into or out of wing 120. In someembodiments, platform 1102 may be a surface within airframe 150 ofaircraft 100. In other embodiments, platform 1102 may be a tendervehicle that supports the entire length of multi-tread vehicle 200 c. Insome embodiments, tread portions and connector portions of multi-treadvehicle 200 c are folded along the top of the tender vehicle, asdescribed in FIGS. 6A-6F. Multiple tender vehicles can be positionedside-by-side to support parallel and/or multiple tasks being conducted.In some embodiments, a tender vehicle is deployed below wing 120 withmulti-tread vehicle 200 c accessing interior 126 of wing 120 through apanel access port and/or opening 124 located at the bottom of wing 120.

As illustrated in FIG. 11B, two tread sections of multi-tread vehicle200 c have advanced into wing 120 and are each supported by one loweredge 125 of one opening 124. As previously described, the length of atread section may be longer than the length of a wing bay compartmentfrom rib to rib, such as from rib 122 a to rib 122 b, such that eachtread section is supported by at least one edge 125 of rib 122 at alltimes. In some embodiments, connector sections are the same length astread sections and keep each subsequent tread section at a distance suchthat multi-tread vehicle 200 with at least two tread section aresimultaneously supported by at least two edges 125 of ribs 122 as itadvances through interior 126 of wing 120. In some embodiments, there isminimal friction build up upon multi-tread vehicle 200 c as each treadon all tread sections are rotating simultaneously to advance multi-treadvehicle 200 c.

FIG. 11C depicts fourth multi-tread vehicle 200 d entering wing 120through an access port opening 124 at outboard end 120 d of wing 120.Because aircraft wings are typically narrower at the tip than at thebase, outboard end 120 d of wing 120 may include fewer access portopenings 124 than the base of wing 120 at inboard end 120 c. For thisreason, openings 124 at outboard end 120 d may also be narrower thanopenings 124 located at inboard end 120 c.

FIG. 11D depicts multi-tread vehicle 200 e comprising two treadsections, 210 a and 210 b, coupled by connector section 280. Multi-treadvehicle 200 e further comprises connecting point 1104 e and tether 1106coupled to tread section 210 b. In some embodiments, tether 1106supplies multi-tread vehicle 200 e with electrical power from a powersource. Tether 1106 may also include piping and/or other tubing toprovide hydraulic power air pressure, and/or data transfer capabilities.In such embodiments, multi-tread vehicle 200 e with tether 1106 canfunction with fewer tread and connector sections, which provides forless complexity and hardware.

In various embodiments, use of multi-tread vehicle 200, as described inthe present disclosure allows for an improved design of wing 120. Use ofmulti-tread vehicle 200 for internal wing tasks eliminates the need fora mechanic to enter into interior 126 of wing 120. This, in turn, allowsfor the elimination of access ports at the bottom and/or top of wing120, which provides for a lighter and more simplified structure becauseless components are needed and the wing skin panels is less pierced orinterrupted by access ports. Additionally, only having to accommodatemulti-tread vehicle 200 and the tools needed to be transported into thewing, instead of a human mechanic, wing 120 can be constructed with athinner profile with a shallower depth, providing less drag and improvedperformance.

Examples of Aircraft and Methods of Fabricating and Operating Aircraft

Examples of the present disclosure may be described in the context ofaircraft manufacturing and service method 1200 as shown in FIG. 12 andaircraft 100 as shown in FIG. 1A. During pre-production, illustrativemethod 1200 may include specification and design (block 1204) ofaircraft 100 and material procurement (block 1206). During production,component and subassembly manufacturing (block 1208) and inspectionsystem integration (block 1210) of aircraft 100 may take place.Described methods and assemblies formed by these methods and includingmulti-tread vehicle can be used in any of specification and design(block 1204) of aircraft 100, material procurement (block 1206),component and subassembly manufacturing (block 1208), and/or inspectionsystem integration (block 1210) of aircraft 100.

Thereafter, aircraft 100 may go through certification and delivery(block 1212) to be placed in service (block 1214). While in service,aircraft 100 may be scheduled for routine maintenance and service (block1216). Routine maintenance and service may include modification,reconfiguration, refurbishment, etc. of one or more inspection systemsof aircraft 100. Described methods and assemblies formed by thesemethods and including multi-tread vehicle can be used in any ofcertification and delivery (block 1212), service (block 1214), and/orroutine maintenance and service (block 1216).

Each of the processes of illustrative method 1200 may be performed orcarried out by an inspection system integrator, a third party, and/or anoperator (e.g., a customer). For the purposes of this description, aninspection system integrator may include, without limitation, any numberof aircraft manufacturers and major-inspection system subcontractors; athird party may include, without limitation, any number of vendors,subcontractors, and suppliers; and an operator may be an airline,leasing company, military entity, service organization, and so on.

As shown in FIG. 1A, aircraft 100 produced by illustrative method 1200may include airframe 150 with an interior 170. As previously described,aircraft 100 further includes right wing 120 and left wing 121 coupledto airframe 150, with engine 130 coupled to right wing 120 and engine131 coupled to left wing 121. Airframe 150 further includes a number ofhigh-level inspection systems such as electrical inspection system 140and environmental inspection system 160. Any number of other inspectionsystems may be included. Although an aerospace example is shown, theprinciples disclosed herein may be applied to other industries, such asthe automotive industry. Accordingly, in addition to aircraft 100, theprinciples disclosed herein may apply to other vehicles, e.g., landvehicles, marine vehicles, space vehicles, etc.

Apparatus(es) and method(s) shown or described herein may be employedduring any one or more of the stages of manufacturing and service method(illustrative method 1200). For example, components or subassembliescorresponding to component and subassembly manufacturing (block 1208)may be fabricated or manufactured in a manner similar to components orsubassemblies produced while aircraft 100 is in service (block 1214).Also, one or more examples of the apparatus(es), method(s), orcombination thereof may be utilized during production stages (block1208) and (block 1210), for example, by substantially expeditingassembly of or reducing the cost of aircraft 100. Similarly, one or moreexamples of the apparatus or method realizations, or a combinationthereof, may be utilized, for example and without limitation, whileaircraft 100 is in service (block 1214) and/or during maintenance andservice (block 1216).

Conclusion

Different examples of the apparatus(es) and method(s) disclosed hereininclude a variety of components, features, and functionalities. Itshould be understood that the various examples of the apparatus(es) andmethod(s) disclosed herein may include any of the components, features,and functionalities of any of the other examples of the apparatus(es)and method(s) disclosed herein in any combination, and all of suchpossibilities are intended to be within the spirit and scope of thepresent disclosure.

Many modifications of examples set forth herein will come to mind to oneskilled in the art to which the present disclosure pertains having thebenefit of the teachings presented in the foregoing descriptions and theassociated drawings.

Therefore, it is to be understood that the present disclosure is not tobe limited to the specific examples illustrated and that modificationsand other examples are intended to be included within the scope of theappended claims. Moreover, although the foregoing description and theassociated drawings describe examples of the present disclosure in thecontext of certain illustrative combinations of elements and/orfunctions, it should be appreciated that different combinations ofelements and/or functions may be provided by alternative implementationswithout departing from the scope of the appended claims. Accordingly,parenthetical reference numerals in the appended claims are presentedfor illustrative purposes only and are not intended to limit the scopeof the claimed subject matter to the specific examples provided in thepresent disclosure.

What is claimed is:
 1. A multi-tread vehicle comprising: a first treadsection comprising a first front tread portion and a first rear treadportion coupled to the first front tread portion, the first front treadportion comprising a first front right tread and a first front lefttread, the first rear tread portion comprising a first rear right treadand a first rear left tread, the first front right tread and the firstfront left tread having different lengths, a second tread sectioncomprising a second front tread portion and a second rear tread portioncoupled to the second front tread portion, the second front treadportion comprising a second front right tread and a second front lefttread, the second rear tread portion comprising a second rear righttread and a second rear left tread; and a connector section coupled tothe first rear tread portion and to the second front tread section. 2.The multi-tread vehicle of claim 1, wherein the first rear tread portionis detachably coupled to the first front tread portion using a firstdetachable tread coupling, and wherein the second rear tread portion isdetachably coupled to the second front tread portion using a seconddetachable tread coupling.
 3. The multi-tread vehicle of claim 1,wherein the first rear tread portion of the first tread sectioncomprises a rear tread pivot coupling pivotably coupled to a frontconnector pivot coupling of the connector section.
 4. The multi-treadvehicle of claim 3, wherein the second front tread portion of the secondtread section comprises a front tread pivot coupling pivotably coupledto a rear connector pivot coupling of the connector section.
 5. Themulti-tread vehicle of claim 4, wherein the multi-tread vehicle isfoldable between an extended state and a folded state, and wherein inthe extended state the first front right tread and the second frontright tread are collinear, and wherein in the folded state the firstfront left tread is disposed between the first front right tread and thesecond front right tread.
 6. The multi-tread vehicle of claim 5, whereinin the folded state the first front left tread is adjacent to andparallel to the second front right tread.
 7. The multi-tread vehicle ofclaim 4, wherein the first front tread portion comprises a first frontpivot axis and a first rear pivot axis, wherein the second front treadportion comprises a second front pivot axis, and wherein a distancebetween the first rear pivot axis and the second front pivot axis isequal to a square root of a sum of a square of a distance between thefirst front pivot axis and first rear pivot axis and a square of adistance between the first front pivot axis and the second front pivotaxis.
 8. The multi-tread vehicle of claim 7, wherein the distancebetween the first front pivot axis and the second front pivot axis isequal to a width of the first tread section.
 9. The multi-tread vehicleof claim 3, wherein the first rear tread portion comprises a rear pivotdrive engaging the connector section for pivoting the connector sectionrelative to the first rear portion.
 10. The multi-tread vehicle of claim3, wherein the first rear portion comprises a rear tread pivot couplingengaging a front connector pivot coupling of the connector section. 11.The multi-tread vehicle of claim 1, wherein a front end of the connectorsection is bendable relative to a rear end of the connector sectionaround a front bend axis parallel to a plane defined by the first rearright tread and the first rear left tread.
 12. The multi-tread vehicleof claim 11, wherein a front connector pivot coupling of the connectorsection is bendable relative to a rear connector pivot coupling of theconnector section around the front bend axis.
 13. The multi-treadvehicle of claim 11, wherein the front end of the connector section isfurther bendable relative to the rear end of the connector sectionaround a rear bend axis parallel to the plane defined by the first rearright tread and the first rear left tread.
 14. The multi-tread vehicleof claim 11, wherein the connector section comprises a front connectorbend drive for bending the front end relative to the rear end of theconnector section around the front bend axis.
 15. The multi-treadvehicle of claim 1, wherein the connector section comprises a frontconnector portion and a rear connector portion detachably coupled to thefront connector portion using a detachable connector coupling.
 16. Themulti-tread vehicle of claim 1, wherein the first front right tread andthe first rear left tread have same lengths.
 17. The multi-tread vehicleof claim 16, wherein the first rear left tread overlaps a right treadgap between the first front right tread and the first rear right tread.18. The multi-tread vehicle of claim 1, wherein the first rear righttread and the first front left tread have same lengths.
 19. A method foraccessing an interior space of aircraft using a multi-tread vehicle, themethod comprising: positioning the multi-tread vehicle at an opening tothe interior space of aircraft, the multi-tread vehicle comprising afirst tread section comprising a first front tread portion and a firstrear tread portion coupled to the first front tread portion, a secondtread section comprising a second front tread portion and a second reartread portion coupled to the second front tread portion, and a connectorsection coupled to the first rear tread portion and to the second fronttread portion; advancing at least the first tread section of themulti-tread vehicle into an opening to the interior space; and bending afront end of the connector section relative to a rear end of theconnector section around a front bend axis parallel to a plane definedby the first rear tread portion using a front connector bend drive ofthe connector section.
 20. A multi-tread vehicle comprising: a firsttread section comprising a first front tread portion and a first reartread portion coupled to the first front tread portion, the first fronttread portion comprising a first front right tread and a first frontleft tread, the first rear tread portion comprising a first rear righttread and a first rear left tread, a second tread section comprising asecond front tread portion and a second rear tread portion coupled tothe second front tread portion, the second front tread portioncomprising a second front right tread and a second front left tread, thesecond rear tread portion comprising a second rear right tread and asecond rear left tread; and a connector section coupled to the firstrear tread portion and to the second front tread section, a front end ofthe connector section being bendable relative to a rear end of theconnector section around a front bend axis parallel to a plane definedby the first rear right tread and the first rear left tread, theconnector section comprising a front connector bend drive for bendingthe front end relative to the rear end of the connector section aroundthe front bend axis.